Same starter as 5.7L and 4.3L; provided you have the same "diagonal" bolt pattern.
YOU HAVE THE WRONG STARTER BOLTS. The shank diameter is WRONG. This can cause DAMAGE.
The "Mini" starters have metric-sized bolt holes, larger than the 3/8 bolt holes of the older, huge "10MT" starter motors.
Since the hole in the block is the same recessed 3/8-16 SAE thread, the correct bolts have a STEPPED SHANK. The main part of the bolt is larger, to fit the larger holes in the starter nose, then necks-down to a smaller diameter knurl and threaded section to fit the smaller holes in the engine block.
Photo 1. GM mini-starter bolts on top, ARP mini-starter bolts still in package.
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Photo 2. Stepped knurl of GM bolts. Good design.
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Photo 3. Stepped shank of ARP bolts. Not as good design. Knurl is loose in starter motor, but at least the shank is correct, larger diameter.
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Photo 4. 10MT vs. PG260 starters, both with "diagonal" bolt pattern for large 168-tooth flywheel. 153-tooth flywheel uses "straight-across" bolt pattern starter nose.
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For the record, while ARP makes good quality bolts...
for this application I believe they're incorrectly designed. The knurl is too small to locate the starter motor. The knurl has to be stepped, so it's tight in the starter AND tight in the block. Buy the GM bolts. The GM bolts are also less expensive.
There's a similar "short" bolt for the engines with the small flywheel and the one-long-one-short starter bolts. I don't remember the part number, but it's in the bulletin linked-to, below.
Remy's TSB for starter motor upgrade:
https://images.carid.com/remy/starting-and-charging/pdf/remy-feb2016-web-technical-bulletin.pdf